Current Distribution Within The Bath Patents (Class 204/DIG7)
  • Patent number: 6139711
    Abstract: An apparatus for measuring the throwing power of electroplating solutions which provides a nearly linear current density distribution across the panel. The apparatus includes a cylindrical body adapted for rotation about a longitudinal axis thereof, a cylindrical cathode arranged coaxially about a central portion of the cylindrical body, an anode coaxially positioned at a lower end portion of the cylindrical body, a conical shield coaxially arranged around an upper end portion of the cathode; and an annular disk-baffle coaxially arranged around a lower end portion of the cathode. The conical shield and the disk-baffle provide a substantially linear current distribution over the cathode.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: October 31, 2000
    Assignee: Lucent Technologies Inc.
    Inventors: Joseph Anthony Abys, Joseph John Maisano, Lars Goran Holmbom
  • Patent number: 6132583
    Abstract: An electroplating system includes a tank that holds an electrolytic bath solution. An anode within the tank receives a first voltage having a first potential. A substrate cathode, immersible in the solution within the tank, spaced from the anode, receives a second voltage having a second potential, opposite to that of the first potential. A shield is immersible in the solution within the tank between the anode and cathode. The level of shielding provided by the shield is variable and controllable. In one embodiment, the shield includes a conductive element that receives a third voltage having the first potential, the magnitude of the third voltage being controllable. In another embodiment, the shield includes at least one louver, the physical orientation of which is controllably adjustable. The shield is sufficiently spaced from the substrate cathode to be substantially outside an area of sparging and is fixed between the anode and cathode.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: October 17, 2000
    Assignee: Technic, Inc.
    Inventor: William M. Stone
  • Patent number: 6132587
    Abstract: The non-uniformity of electroplating on wafers is due to the appreciable resistance of the thin seed layer and edge effects. Mathematical analysis of the current distribution during wafer electroplating reveals that the ratio between the resistance of the thin deposited seed layer and the resistance of the electrolyte and the electrochemical reaction determines the uniformity of the electroplated layer. Uniform plating is critical-in-wafer metallization for the subsequent step of chemical mechanical polishing of the wafer. Based on the analysis, methods to improve the uniformity of metal electroplating over the entire wafer include increasing the resistance of the electrolyte, increasing the distance between the wafer and the anode, increasing the thickness of the seed layer, increasing the ionic resistance of a porous separator placed between the wafer and the anode, placement of a rotating distributor in front of the wafer, and establishing contacts at the center of the wafer.
    Type: Grant
    Filed: October 19, 1998
    Date of Patent: October 17, 2000
    Inventors: Jacob Jorne, Judith Ann Love
  • Patent number: 6113755
    Abstract: This invention provides an apparatus for producing an electrode foil for use in aluminum electrolytic capacitors with which a high capacitance is obtained while the distortion of the foil and the leakage current can be controlled. At least two electrode plates as cathode are disposed in an electrolytic tank containing an electrolytic solution, and a direct current is supplied between an aluminum foil as anode and the electrode plates. Anodization is conducted continuously by turning the direction of the aluminum foil via rollers and conveying the foil between the electrode plates. During this treatment, the length and the position of the effective sections of the electrode plates are adjusted to keep the length to be at most two-thirds of the distance between an area near the surface of the electrolytic solution and the upper part of the bottom roller, so that the peak value of the anodizing current density appears not at the surface of the electrolytic solution but in the electrolytic solution.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: September 5, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masakazu Tanahashi, Kounosuke Hashio, Mitsuhisa Yoshimura, Daisuke Suzuki, Masanori Okabayashi, Shinji Kabeya
  • Patent number: 6039858
    Abstract: A method and apparatus are provided for the electroplating on only one side of a substrate immersed in an electroplating bath comprising using a specially designed device which holds the substrate to be plated in spaced relation to an inhibitor electrode which is part of the device. To fabricate x-ray masks, a boron doped silicon substrate is secured to a dielectric clamp which clamp has a through opening which is positioned to overlie the inhibitor electrode. A cathode structure overlies the clamp and the cathode structure, substrate and clamp are secured to the device by preferably a pivotable, locking mechanism. A space is formed between the back side of the substrate and the surface of the inhibitor electrode so that plating is preferentially on the surface of the inhibitor electrode. The use of the method and apparatus minimizes plating on the backside of the substrate and provides a plated substrate on only the upper side of the substrate.
    Type: Grant
    Filed: July 22, 1998
    Date of Patent: March 21, 2000
    Assignee: International Business Machines Corporation
    Inventors: Robin J. Ackel, Douglas E. Benoit, Michael H. Charland, Thomas B. Faure
  • Patent number: 6033540
    Abstract: The present invention provides for a plating apparatus and a method of plating, which improve the uniformity of a plated coating thickness without changing the flow velocity of a feed plating solution. An aperture can be provided at a center of a meshed anode electrode of the plating apparatus to obtain an electric field density distribution between the meshed anode electrode and a wafer that is lower in the central portion of the wafer than in the edge portion of the wafer.
    Type: Grant
    Filed: November 19, 1997
    Date of Patent: March 7, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Katsuya Kosaki, Masahiro Tamaki
  • Patent number: 6027631
    Abstract: An electroplating system includes shield(s) to control the thickness profile of a metal electrodeposited onto a substrate. The shield(s) are positioned between the anode and the cathode in a standard electroplating apparatus with a device for rotating the plating surface. The cathode is rotated so that the shield(s) in conjunction with the rotation of the cathode selectively alters or modulates a time average of the electric field characteristics between the anode and the cathode. The modulated electric field is used to control the electrodeposition rate at selected area(s) of the plating surface of the cathode, thereby causing the metal deposited on the cathode to have a modified thickness profile.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: February 22, 2000
    Assignee: Novellus Systems, Inc.
    Inventor: Eliot K. Broadbent
  • Patent number: 6004440
    Abstract: A cathode current control system employing a current thief for use in electroplating a wafer is set forth. The current thief comprises a plurality of conductive segments disposed to substantially surround a peripheral region of the wafer. A first plurality of resistance devices are used, each associated with a respective one of the plurality of conductive segments. The resistance devices are used to regulate current through the respective conductive finger during electroplating of the wafer. Various constructions are used for the current thief and further conductive elements, such as fingers, may also be employed in the system. As with the conductive segments, current through the fingers may also be individually controlled. In accordance with one embodiment of the overall system, selection of the resistance of each respective resistance devices is automatically controlled in accordance with predetermined programming.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: December 21, 1999
    Assignee: Semitool, Inc.
    Inventors: Kyle M. Hanson, K. Chris Haugan, Kevin W. Coyle, James Doolittle, Robert W. Berner
  • Patent number: 6001235
    Abstract: A rotary plater and method of plating are provided which improve the uniformity of plating across a plating surface of a workpiece. A plating solution distribution device is located in a plating cup between an anode and a cathode in a spaced relationship therebetween and is centered about a vertical axis of the plating cup. A motor is provided for relatively rotating the cathode and the plating solution distribution device with respect to one another. The plating solution distribution device distributes the plating solution over the plating surface at a distribution rate which increases radially outwardly from the vertical axis. With this arrangement the volume of plating solution at the outer periphery of the plating surface is enriched with ions to promote plating uniformity.
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: December 14, 1999
    Assignee: International Business Machines Corporation
    Inventors: David M. Arken, Andrew Chiu, Joseph John Fatula, Jr., Robert William Hitzfield, Wen-Chien David Hsiao, Yiping Hsiao
  • Patent number: 5985123
    Abstract: An electroplating apparatus comprising: an electroplating tank assembly for receiving an electroplating solution; transfer structure for transferring a substrate to be electroplated along a transfer passage within the electroplating tank assembly; at least one pair of sparger assemblies for dispersing the electroplating solution in the direction of the substrate; at least one pair of anode baskets for containing anode material; electricity feeding circuitry for feeding electricity to the anode material contained in the at least one pair of anode baskets; and at least one pair of anode shield assemblies positioned to direct a current flux toward the substrate to provide for a uniform distribution of plating material thereon.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: November 16, 1999
    Inventor: Kam Kwan Koon
  • Patent number: 5958206
    Abstract: The invention relates to a method to produce an oxide coating that protects against corrosion and wear on the metal surface of a workpiece, more specifically, for the metal surface of a body for accepting a valve, wherein with the use of a cathode, the workpiece, as an anode, is subjected to constant or pulsating direct current in an electrolyte, with an auxiliary anode, which is resistant to the electrolyte, being attached to the workpiece before the workpiece is dipped into the electrolyte, which discharges the anodizing current at locations where no anodized coating is required or only a limited anodized coating is required.
    Type: Grant
    Filed: August 21, 1997
    Date of Patent: September 28, 1999
    Assignee: ITT Manufacturing Enterprises Inc.
    Inventors: Horst Rothbauer, Ewald Renner
  • Patent number: 5932077
    Abstract: A wet process apparatus, e.g., plating cell for plating a flat substrate introduces a flow of electrolyte or other plating solution across the surface of the substrate to be plated. The substrate is mounted on a holder that is positioned on a door that swings between a horizontal open position and a vertical closed position. There is a circular opening in a front wall against which the door seats. The door can have a sealing ring that contacts the wall of the cell outside of the opening. A cathode ring disposed in a recess in the periphery of the opening makes electrical contact with the substrate. The cathode ring can include a thin metal thieving ring. A fluid-powered rotary blade or wiper within the plating chamber rotates to draw bubbles or other impurities from the substrate, and a megasonic transducer applies megasonic acoustic energy to the solution, e.g., at 0.2 to 5 Mhz. The cell can be used for electroless or galvanic plating.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: August 3, 1999
    Assignee: Reynolds Tech Fabricators, Inc.
    Inventor: H. Vincent Reynolds
  • Patent number: 5804052
    Abstract: The invention relates to a method for continuous uniform electrolytic metallizing or etching of metal surfaces, and to a device suitable for carrying out this method. The invention is particularly suitable for treating printed circuit boards and conductive films in installations through which the metal surface being treated passes horizontally. In order to avoid metal coatings of differing thicknesses being deposited on narrow and wide conductor strips in printed circuit boards, according to the present invention operation is with movable, preferably rotating roller-shaped intermediate electrodes, which roll without short circuit at a very close effective distance above the metal surface being treated, or which contact the surface in a wiping manner. These intermediate electrodes are not electrically connected to the source of bath current, thus serving as bipolar electrodes, and are located between the surface being treated and a suitable counter-electrode.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: September 8, 1998
    Assignee: Atotech Deutschland GmbH
    Inventor: Reinhard Schneider
  • Patent number: 5788829
    Abstract: A method and apparatus for electroplating a workpiece to achieve a uniform plating thickness includes a cathode rack having a hook from which the workpiece is suspended and spaced apart from a consumable anode. The rack includes a plurality of plates made of the same material as the anode disposed on opposite sides of the rack. The plates direct a portion of the current emanating from the anode away from the workpiece to produce more uniform plating.
    Type: Grant
    Filed: October 16, 1996
    Date of Patent: August 4, 1998
    Assignee: Mitsubishi Semiconductor America, Inc.
    Inventors: Swati V. Joshi, Robert R. Botts, Louis W. Nicholls
  • Patent number: 5776327
    Abstract: A method and apparatus are provided for electroplating a workpiece. The apparatus includes an anode basket containing particles of an electroplating material. A mask is positioned around the anode basket to selectively block current flow from the basket to the workpiece which is mounted to a cathode. The mask includes a frame supporting a number of non-conductive plates adjusted in position to provide a desired electrical field distribution. The resulting electrical field between the anode and the cathode produces uniform plating thickness over the entire surface of the workpiece.
    Type: Grant
    Filed: October 16, 1996
    Date of Patent: July 7, 1998
    Assignee: Mitsubishi Semiconuctor Americe, Inc.
    Inventors: Robert R. Botts, Swati V. Joshi, Louis W. Nicholls
  • Patent number: 5670034
    Abstract: A plating system (10) for plating a substrate such as a semiconductor wafer (116) in an electrolytic tank (12). A fixture wheel (14) is mounted within the electrolytic tank to rotate about a first axis (140). The fixture wheel receives the semiconductor wafer and supplies electrical current to the perimeter edge of the wafer. A fixture wheel drive motor (90) drives rotation of the fixture wheel about the first axis. An anode assembly (18) is mounted in the tank spaced from and facing towards the fixture wheel and received semiconductor wafer. The anode assembly carries first and second anodes (72) which are supplied with electrical current. A second motor (142) causes reciprocation of the anode assembly transversely in front of the rotating fixture wheel for improved uniformity in plating thickness and composition.
    Type: Grant
    Filed: June 17, 1996
    Date of Patent: September 23, 1997
    Assignee: American Plating Systems
    Inventor: Kenneth J. Lowery
  • Patent number: 5589051
    Abstract: A clamp for use in an electrolytic plating bath is disclosed. The clamp comprises two levers pivotally attached to each other at a fulcrum wherein the clamp, when floating on top of a liquid, is in an open position but when submerged is caused, by virtue of its buoyancy, to move to a closed position. Each lever comprises a first part integrally attached to a second part. The first part and the second part are situated on opposite sides of the fulcrum from each other such that rotational movement about the fulcrum between the open position and the closed position causes the second parts of each lever to move from an upper position to a lower position. In operation, at least one substrate is supported in a substantially vertical plane for submersion into an electrolyte bath. The substrate is positioned over the electrolyte bath and then is submersed into it. The clamp clamps the substrate at its lower edge as the substrate enters the electrolyte bath.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: December 31, 1996
    Assignee: Process Automation International Limited
    Inventor: Paul Henington
  • Patent number: 5516412
    Abstract: An electroplating cell includes a floor, ceiling, front wall, and back wall forming a box having first and second opposite open ends. A rack for supporting an article to be electroplated is removably positioned vertically to close the first open end and includes a thief laterally surrounding the article to define a cathode. An anode is positioned vertically to close the second open end, with the assembly defining a substantially closed, six-sided inner chamber for receiving an electrolyte therein for electroplating the article. The article and surrounding thief are coextensively aligned with the anode, with the floor, ceiling, front and back walls being effective for guiding electrical current flux between the cathode and the anode. In a preferred embodiment, the cell is disposed as an inner cell inside an outer cell substantially filled with the electrolyte, and a paddle is disposed inside the inner cell for agitating the electrolyte therein.
    Type: Grant
    Filed: May 16, 1995
    Date of Patent: May 14, 1996
    Assignee: International Business Machines Corporation
    Inventors: Panayotis C. Andricacos, Kirk G. Berridge, John O. Dukovic, Matteo Flotta, Jose Ordonez, Helmut R. Poweleit, Jeffrey S. Richter, Lubomyr T. Romankiw, Otto P. Schick, Frank Spera, Kwong-Hon Wong
  • Patent number: 5476577
    Abstract: In a device for the electrolytic deposition of metal on the metal strips (1) forming the cathode, which are taken through a gap in an electrolyte (3) between two flat or rod-like parallel anodes (2), the proposal is for edge masks (4) to screen off the edge regions of the metal strip (1). The shanks (41 ) of each edge mask (4) are prestressed by springs against the anodes (2) and their relatively wide shanks may be directed transversely to the direction of the strip in order to take transitions between different strip widths into account.
    Type: Grant
    Filed: August 31, 1994
    Date of Patent: December 19, 1995
    Inventors: Hans J. May, Roland Schnettler
  • Patent number: 5472735
    Abstract: The present invention relates to a method for selectively electroetching a metal from an electrical device having the steps of: immersing the electrical device in an etching solution; immersing a cathode in the etching solution; applying an etching potential to a preselected area of the metal; and maintaining a passivation potential at the metal to remain unetched. The metal to remain unetched is not electrically connected to the preselected area and the passivation potential does not equal the etching potential.The present invention further relates to a method of forming an electrical connection to the inner layers of a multilayer circuit board having a copper foil surface layer and copper containing inner layers.
    Type: Grant
    Filed: December 8, 1994
    Date of Patent: December 5, 1995
    Assignee: International Business Machines Corporation
    Inventors: Christina M. Boyko, Richard W. Carpenter, Raymond T. Galasco, Krystyna W. Semkow, Herbert Wegener
  • Patent number: 5413692
    Abstract: Electrodeposition in surface finishing as well as in electroforming can be performed in a broad range of hydrodynamic conditions. In some instances, such as barrel plating, the liquid is barely moving relative to the work piece, while in jet plating the solution moves up to several meters per second relative to the piece to be plated. In such a wide range of hydrodynamic conditions, the selection of appropriate quality control (QC) methods for each particular operation is very critical. The QC method has to resemble the manufacturing operation in terms of the hydrodynamic conditions otherwise the quality control and the functional test for the bath performance have no meaning. Available Hull Cell systems have a limited capability in varying the liquid velocity. At best a relative velocity of up to 20 or perhaps 30 cm/sec can be achieved with uneven distribution.
    Type: Grant
    Filed: March 31, 1993
    Date of Patent: May 9, 1995
    Inventors: Joseph A. Abys, Igor V. Kadija
  • Patent number: 5401370
    Abstract: The invention builds on an arrangement for the masking of field lines in an electroplating plant for the treatment of essentially plate-shaped workpieces, which are loaded into the bath suspended from a workpiece holder, wherein a mask is provided which is vertically adjustably guided on the plating tank. To permit the vertical adjustment of the mask regardless of the shape and, in particular, the thickness of the workpiece to be treated, as well as the manner in which the workpiece is held on the workpiece holder, and further, so that said mask(s) can optionally mask the lower or the upper area of the workpiece(s) to be treated, a hold-down clamp (21) is provided, attached to the workpiece holder (6) in such a way as to be height-adjustable and lockable in the particular position, and moves the masks (12, 13; 14, 15) located laterally to the workpieces (5) into a preselected position as the workpiece holder (6) is loaded into the treatment station (1).
    Type: Grant
    Filed: October 6, 1992
    Date of Patent: March 28, 1995
    Assignee: Atotech Deutschland GmbH
    Inventors: Rudolf Kauper, Gerhard Wilhelm
  • Patent number: 5391276
    Abstract: The invention relates to a device for screening off lines of electric flux in an installation for electrolytic processing of substantially plate-shaped material in the form of one or more workpieces which is held underneath a goods carrier and immersed in a bath when the goods carrier is lowered. A screen is provided which is adjustable in the vertical direction by a hold-down mechanism which is coupled with the movement of the goods carrier. The hold-down mechanism includes rods which project downward from the goods carrier to bear on two end regions of the screen. The lower ends of the rods and the end regions of the screen are constructed in such a way that the screen cannot be displaced relative to the rods at least in its longitudinal direction. The distance between the rods is greater than the width of the material to be processed which is located between the rods during processing.
    Type: Grant
    Filed: October 28, 1993
    Date of Patent: February 21, 1995
    Assignee: Atotech Deutschland GmH
    Inventors: Kurt Astor, Peter Haase, Manfred Gute
  • Patent number: 5332487
    Abstract: A method of and an apparatus for the electroplating of material onto substrates, such as computer memory disks, by use of a plating cell comprising cathodes, anodes, passive shields, filters, an oscillation system and an electrical power supply. Anodes and magnets are attached to the inside side walls of the plating cell. The magnets have a coating of an electrically nonconducting material covering it. Shields, each having a filter attached to it, are also fixed to the inside side walls. A pallet, having openings for holding disk substrates during electroplating, is placed between the shields in the plating cell. The disk substrates function as cathodes during electrolytic plating. The anodes and cathodes when electrically energized results in deposition of desired material, having uniform thickness, across the entire surface area of the substrate.
    Type: Grant
    Filed: April 22, 1993
    Date of Patent: July 26, 1994
    Assignee: Digital Equipment Corporation
    Inventors: David J. Young, Jr., Scott L. Randall, Scott D. Shaw, Andrew F. Wylde
  • Patent number: 5312532
    Abstract: A multi-compartment electroplating system for electroplating two or more objects simultaneously such that the electrodeposited material is substantially uniform in thickness and composition. Electroplating solution is circulated between a reservoir and a multi-compartment tank which has one cathode-paddle-anode (CPA) assembly for each compartment. Each CPA assembly has an anode, a cathode adapted for holding a wafer and employing a single thieving electrode which covers all of the floor of the compartment not covered by the wafer, and a paddle. Also included is a cover which houses a single linear motor for driving all of the paddles in synchrony.
    Type: Grant
    Filed: January 15, 1993
    Date of Patent: May 17, 1994
    Assignee: International Business Machines Corporation
    Inventors: Panayotis Andricacos, Moritz Branger, Robert M. Browne, John O. Dukovic, Benjamin W. B. Fu, Robert W. Hitzfeld, Matteo Flotta, Donald R. McKenna, Lubomyr T. Romankiw, Saeed Sahami
  • Patent number: 5275711
    Abstract: This invention pertains to an apparatus and method for measuring throwing power of electroplating solutions. The apparatus is easy to use and gives reproducible measurements. The apparatus emulates the performance of a conventional Haring Blum cell. The major disadvantage of the standard Haring Blum cell is its limited aility to vary the solution mass transport, thus limiting its applicability to very low current density applications. Furthermore, even under low-mass transport conditions, non-uniform solution distribution is experienced leading to erroneous interpretation. This invention permits the study of throwing power of electroplating solutions under a whole variety of solution agitation. The invention embodies an instrument for and a method of measuring the throwing power of electrolytes.
    Type: Grant
    Filed: June 19, 1992
    Date of Patent: January 4, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Joseph A. Abys, Igor V. Kadija, Joseph J. Maisano, Jr.
  • Patent number: 5256262
    Abstract: An electrolytic deburring system and method employing a relatively weakly conducting electrolyte with the cathode immersed in the electrolyte in which an anodic potential is applied to the workpiece being deburred. A conductive element acting as a virtual cathode is placed between the cathode and the part to provide a more conductive path than the existing path through the electrolyte to concentrate deburring action and/or shield a portion of the workpiece from the deburring action.For deburring a multiplicity of parts at the same time, two electrodes are immersed in the electrolyte and a potential difference is applied between them. Spaced parts placed between the electrodes assume potential differences leading to selective material removal from the relatively anodic portions of each part. The polarity of the applied potential may be reversed, thereby reversing the polarity of the potential differences between the parts to selectively remove material from the newly anodic portions of the parts.
    Type: Grant
    Filed: May 8, 1992
    Date of Patent: October 26, 1993
    Inventor: Karl-Ingemar Blomsterberg
  • Patent number: 5228976
    Abstract: The invention provides, in electroplating quality control methods for manufacturing, better similarity and relevance between a Hull Cell quality control test and a particular plating operation. The invention is a simple and yet functional instrument which can be used to identify the performance of the plating bath prior to manufacturing operation under similar hydrodynamic conditions. The instrument is a rotating cylinder with a flexible Cu test panel attached to its surface. Like a Hull Cell, a range of current density can be simultaneously applied. Unlike a Hull Cell, the rotating speed of the cylinder and hence the solution agitation is practically unlimited. The operator can identify the operating window for the particular process and apply them to the production line. The instrument has also demonstrated usefulness in developing proprietary electroplating chemistries.
    Type: Grant
    Filed: July 9, 1990
    Date of Patent: July 20, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Joseph A. Abys, Igor V. Kadija
  • Patent number: 5135636
    Abstract: A plating rack for use in electroplating at least one substrate includes a rack body onto which the substrate may be placed; a metal ring connected to the rack body so as to surround a substrate placed on the rack body; and bistable, single-tipped cam assemblies for holding a placed substrate in place and for making electrical contact between the metal ring and the substrate.
    Type: Grant
    Filed: September 19, 1991
    Date of Patent: August 4, 1992
    Assignee: Microelectronics and Computer Technology Corporation
    Inventors: Ian Y. K. Yee, James D. Wehrly, Jr.
  • Patent number: 5096550
    Abstract: In an electropolishing or electrolytic etching apparatus the anode is separated from the cathode to prevent bubble transport to the anode and to produce a uniform current distribution at the anode by means of a solid nonconducting anode-cathode barrier. The anode extends into the top of the barrier and the cathode is outside the barrier. A virtual cathode hole formed in the bottom of the barrier below the level of the cathode permits current flow while preventing bubble transport. The anode is rotatable and oriented horizontally facing down. An extended anode is formed by mounting the workpiece in a holder which extends the electropolishing or etching area beyond the edge of the workpiece to reduce edge effects at the workpiece. A reference electrode controls cell voltage. Endpoint detection and current shut-off stop polishing. Spatially uniform polishing or etching can be rapidly performed.
    Type: Grant
    Filed: October 15, 1990
    Date of Patent: March 17, 1992
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Steven T. Mayer, Robert J. Contolini, Anthony F. Bernhardt
  • Patent number: 5084153
    Abstract: The maximum acceptable operating current of an electrode immersed in an electrically conductive liquid is increased by providing at least one shield member in front of the electrode and serving to reduce the current density at the part or parts of the electrode where current density would otherwise be highest.
    Type: Grant
    Filed: December 11, 1990
    Date of Patent: January 28, 1992
    Assignee: Beckswift Limited
    Inventors: Richard W. E. Mosse, Jan R. Van Der Post
  • Patent number: 4964964
    Abstract: An electroplating rack is constructed of corrosion resistant stainless steel, with oppposed side frames milled with vertical channels to accommodate opposite side edge portions of a printed circuit board for plating. Mechanical and electrical connections with the circuit board are made with recessed stainless steel screws with rounded tips. Current is provided to the top of the rack, and also to the bottom of each side frame through an elongate, vertically disposed copper bar surrounded by an insulative sheath and contained within each side frame. Each of the copper rods is threadedly engaged in a steel end cap at the bottom of the associated frame. The current fed into the top and bottom of the rack can be adjusted by adjusting the comparative conductivity of the two paths.
    Type: Grant
    Filed: April 3, 1989
    Date of Patent: October 23, 1990
    Assignee: Unisys Corporation
    Inventor: Timothy I. Murphy
  • Patent number: 4950375
    Abstract: A die for electroforming a nickel sheath thereon is provided with a groove filled with a non-conductive material at the desired dimension of the sheath. The die has an exposed portion beyond the dimensions of the sheath.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: August 21, 1990
    Assignee: United Technologies Corporation
    Inventor: Donald F. Leger
  • Patent number: 4933061
    Abstract: An electroplating apparatus for electroplating a plurality of items. The apparatus includes a tank having a bottom wall and side walls and adapted to hold a predetermined quantity of an electrolytic plating solution. A sparger system at the bottom of the tank directs the electrolytic plating solution in an upward direction. A cathode rack supporting the items to be electroplated extends intermediate to anode plates and upwardly from the sparger system. Strategically placed openings in the anodes and an anode screen in conjunction with the sparger system act to reduce the plating thickness variance over the rack.
    Type: Grant
    Filed: December 29, 1988
    Date of Patent: June 12, 1990
    Assignee: Trifari, Krussman & Fishel, Inc.
    Inventors: Krishna Kulkarni, Richard J. DiDonato
  • Patent number: 4879007
    Abstract: A floating shield is provided for use in an electrolytic plating bath. The shield comprises an elongated trough in which substrates are loaded for plating. The substrates are held in the trough with the lower edge of each substrate below the plane of the edges of the trough. The trough prior to loading is sufficiently buoyant to float on the surface of the electrolyte but sinks into the bath after loading with substrates. In one embodiment the trough is slidably mounted for reciprocating vertical movement in guide members which form part of a mechanical agitator mounted in the bath. The floating shield device serves to facilitate deposition of a uniformly thick layer of metal on the substrate and avoids excessive deposition at the lower extremities of the substrate.
    Type: Grant
    Filed: December 12, 1988
    Date of Patent: November 7, 1989
    Assignee: Process Automation Int'l Ltd.
    Inventor: Chi W. Wong
  • Patent number: 4855020
    Abstract: An apparatus for the electrolytic plating of computer memory discs comprising a plating container for the receipt of a liquid plating bath, a spindle fitted to the plating container, a prime mover connected to the spindle for causing relative rotational movement, a fixed and non-translatable stationary anode attached to the plating container, an electrical transmission system connected to the spindle and to the anode, and suitable current distribution controllers positioned within the plating container. The spindle has a receiving area for fixing to the inner diameter of a computer memory disc. The stationary anode is positioned on opposite sides of the receiving area of the spindle. The electrical transmission system includes a contact surface for establishing electrical contact with the edge of a computer memory disc. The current distribution controllers are adjacent the contact surface of the electrical conductors.
    Type: Grant
    Filed: January 12, 1988
    Date of Patent: August 8, 1989
    Assignee: Microsurface Technology Corp.
    Inventor: Michael A. Sirbola
  • Patent number: 4802960
    Abstract: In an electrolysis cell, a separator having a buried wire screen is disclosed. The screen is connected to a bias voltage source to repel unwanted ionic migration across the screen and hence the separator.
    Type: Grant
    Filed: February 4, 1986
    Date of Patent: February 7, 1989
    Assignee: The Dow Chemical Company
    Inventors: Glenn A. Eisman, Lloyd E. Alexander
  • Patent number: 4720330
    Abstract: The invention is a device and method for electroplating a metal workpiece having axial symmetry, such as a circular workpiece. In this invention the workpiece, which is the cathode, is rotated inside an anode structure submerged in the plating solution. Part of the rotating cathode continuously moves through a region of intense current fluxes created by passing DC current between the anode and cathode. The rotating cathode stirs the plating solution, which speeds up the plating rate. At the same time, with only part of the cathode passing continuously through the intense current flux region, the deposition process is periodically slowed down and intensified.
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: January 19, 1988
    Assignee: The Dow Chemical Company
    Inventors: Mani Shabrang, Daniel A. Gokey
  • Patent number: 4678545
    Abstract: Printed circuit boards and methods for uniformly electroplating narrow, closely spaced circuitry lines onto such a circuit board substrates are disclosed. The method comprises providing an electroplating tank containing an electroplating solution with at least one anode immersed therein. A conductive metal screen is immersed in and extends across the electroplating solution at a solution spaced apart from such an anodes. A printed circuit board substrate is then placed into the electroplating solution at a position wherein the screen is between the anode and the substrate. Copper is then simultaneously plated onto the printed circuit board substrate at a first voltage and onto the screen at a second voltage when the second voltage is less than the first voltage.
    Type: Grant
    Filed: June 12, 1986
    Date of Patent: July 7, 1987
    Inventor: George M. Galik
  • Patent number: 4659446
    Abstract: For electroplating of printing cylinders or the like, cup-like shields of non-conductive acid-resistant material are secured at opposite ends of the cylinder for rotation with the cylinder, the shields extending radially outwardly and having a configuration such as to obtain a field distribution by which the metal deposited on the surface of the cylinder is of substantially uniform thickness and density throughout the length of the cylinder.
    Type: Grant
    Filed: May 15, 1985
    Date of Patent: April 21, 1987
    Assignee: Hallmark Cards, Inc.
    Inventors: Donald A. Shafer, Ronald Walker, Clarence Yeo
  • Patent number: 4569728
    Abstract: Apparatus and method for selectively controlling anodic oxide growth on semiconductors for controlled electrochemical pattern generation incorporating use of a writing beam of a wavelength which encourages oxide growth and a bias beam at a wavelength which discourages oxide growth. The bias beam is projected on the semiconductor in electrolytic environment to prevent or retard oxide growth while oxide growth is accelerated at points of illumination by means of writing beam.
    Type: Grant
    Filed: November 1, 1984
    Date of Patent: February 11, 1986
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Bijan Davari, Pankaj K. Das
  • Patent number: 4548685
    Abstract: In a process for electrolytically removing metal deposit from a non-plated surface of a single surface-plated metal strip, by bringing, within an electrolytic liquid, a single surface-plated metal strip which serves as an anode plate, into a location at which the non-plated surface of the anode single surface-plated metal strip faces in parallel to and is spaced from a cathode plate, and by applying a principal voltage between the anode metal strip and said cathode plate to electrolytically remove metal deposit from the non-plated surface; whereby undesirable stripping of portions of the plated metal layer in side edge portions of the plated surface of the metal strip is prevented by arranging supplementary anode plates within the electrolytic liquid in such a manner that the supplementary anode plates face in parallel to and are spaced from side edge portions of the plated surface of the anode metal strip, and then, while the principal voltage is applied between the anode metal strip and the cathode plate, a
    Type: Grant
    Filed: August 23, 1984
    Date of Patent: October 22, 1985
    Assignee: Nippon Steel Corporation
    Inventors: Yukimasa Suemitsu, Kazutsugu Nakajima, Ryoichi Naka, Hiroo Goshi
  • Patent number: 4534832
    Abstract: A circuit board having a foil bonded to it and connected to serve as a cathode, faces an anode with an interposed shield of sections each of a plurality of horizontally disposed slats. The slats are uniformly spaced center to center, but upper sections of slats have a larger width in the vertical direction than slats of successively lower sections, so that the anode is more exposed in line-of-sight to the upper portions of the cathode foil than the lower sections. Therefore, in plating there is some compensation for the variation in voltage which occurs due to current flow from the upper connection of the cathode foil to the negative terminal. A sparger tube vertically oriented supports the slats. The tube is apertured between each slat and the apertures face the cathode. Electrolyte forced through the sparger tube and then through its openings serves to provide solution agitation for the cathode.
    Type: Grant
    Filed: August 27, 1984
    Date of Patent: August 13, 1985
    Assignee: Emtek, Inc.
    Inventor: Laurea Doiron, Jr.
  • Patent number: 4519876
    Abstract: An improved laser-based method of depositing a metal on an electrically insulated metallic substrate is disclosed. Selected areas of the insulated plate such as an anodized aluminum plate are irradiated with laser energy to fracture the anodized layer and expose underlying aluminum. The plate is immersed in a solution containing copper ions and negatively biased so that a thin layer of copper is electrolytically deposited in the selected areas to form copper features. The method is particularly suited to the rapid production of high quality, durable photographic printing plates with long shelf life.
    Type: Grant
    Filed: June 28, 1984
    Date of Patent: May 28, 1985
    Assignee: Thermo Electron Corporation
    Inventors: Chung H. Lee, John Fronduto, Peter E. Oettinger
  • Patent number: 4507180
    Abstract: The invention relates to a method for the electrodeposition of a homogeneously thick metal layer on the surface of a substantially flat cathode in which a screening member is placed in the electrolyte bath between the planes of the anode and the cathode. In order to improve the homogeneity of the thickness of the metal layer, which is desired, for example, in the manufacture of information carriers, a cylindrical screening member is used which is placed at a short distance from the cathode.
    Type: Grant
    Filed: March 9, 1984
    Date of Patent: March 26, 1985
    Assignee: U.S. Philips Corporation
    Inventors: Bernardus T. van der Werf, Gustaaf H. A. van der Hoorn
  • Patent number: 4497693
    Abstract: A method and apparatus for plating an article having a portion that needs no plating at a high speed including as main components a chuck for chucking the article at the portion above stated and a shield cover for enclosing the chuck, maintaining a space therebetween. The space indicated above works to prevent an electrolyte from raising its level, thus keeping said portion out of said the electrolyte.
    Type: Grant
    Filed: March 22, 1984
    Date of Patent: February 5, 1985
    Assignee: Nippondenso Co., Ltd.
    Inventors: Ken Ogura, Nobuhiko Yamada, Hiroshi Ohmi
  • Patent number: 4490230
    Abstract: There is disclosed electroplating apparatus in which a plurality of anodes and a twice-as-large plurality of first and second cathodes are disposed in a cell such that each anode has on its opposite sides a first cathode and a second cathode, respectively. First and second adjustable constant current sources supply current to, respectively, all first cathodes and such anodes and all second cathodes and such anodes. A plurality of current adjusting units respective corresponding to the anodes are connected on the anodic side of each such current source between that source and each respective anode. The anodes are permanently installed in the cell, while the cathodes are carried by a holder fitting over the top of the cell and removable therefrom. The cathodes may be selectively inserted into guideways in their holder and then locked in place in these guideways until removal of the cathodes is desired, when they are unlocked.
    Type: Grant
    Filed: March 10, 1983
    Date of Patent: December 25, 1984
    Assignee: AT&T Technologies, Inc.
    Inventor: Ivan M. Fletcher
  • Patent number: 4483749
    Abstract: Here are disclosed a method and apparatus for making it possible to plate specific parts of members to be plated to be high in the precision and quality even in minute area parts.In highly integrated printed base plates and integrated circuit elements, it has been difficult to plate precious metals high in the specific conductivity precisely and uniformly in the required minute parts with a plating apparatus in order to control as much as possible the resistances and impedances in the respective terminals and contacts.
    Type: Grant
    Filed: June 28, 1983
    Date of Patent: November 20, 1984
    Assignee: Sonix Ltd.
    Inventor: Koichi Shimamura
  • Patent number: 4482445
    Abstract: Methods and apparatus for electrochemically deburring perforate metallic clad dielectric laminates such, for example, as laminated printed circuit boards (PCBs) or printed wiring boards (PWBs) and similar machined and fabricated laminated dielectric parts; and, more specifically, methods and apparatus for removing burrs formed during drilling, punching and similar machining operations for forming holes in a workpiece and wherein the conductive path for current flow during the electrochemical deburring process extends through the thru-hole perforations formed in the workpiece being deburred so as to concentrate current densities and preferential electrochemical attack in the regions of the clad at the peripheral edges of the thru-hole perforations in the clad dielectric laminate.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: November 13, 1984
    Assignee: The Boeing Company
    Inventor: Joseph C. Fjelstad
  • Patent number: 4469566
    Abstract: A process and apparatus for producing magnetic memory disks, and the like, of the type in which a thin layer of fine grain nickel/phosphorous paramagnetic material is first deposited on a large grain electrically conductive substrate, and a main magnetic layer is then electroplated over the nickel/phosphorous paramagnetic layer. In the practice of the method of the invention, the paramagnetic layer is electroplated onto the substrate through one or more openings in one or more rotating masks to provide directly a smooth fine grain layer of uniform density and thickness so as to obviate any necessity for time consuming and expensive polishing and burnishing operations of the paramagnetic film prior to the electroplating thereon of the main magnetic film; and the magnetic layer is also electroplated onto the paramagnetic layer through openings in one or more masks to provide a magnetic layer of controlled thickness for uniform magnetic response over the entire surface of the disk.
    Type: Grant
    Filed: August 29, 1983
    Date of Patent: September 4, 1984
    Assignee: Dynamic Disk, Inc.
    Inventor: Daniel X. Wray